element not found when using webview2 in wpf

When starting my wpf app with webview2, I alwasys get an 'element not found' exception

this is the message

System.Runtime.InteropServices.COMException (0x80070490): element not found (异常来自 HRESULT:0x80070490) 在 System.Runtime.InteropServices.Marshal.ThrowExceptionForHRInternal(Int32 errorCode, IntPtr errorInfo) 在 Microsoft.Web.WebView2.Core.CoreWebView2Environment.d__80.MoveNext() --- 引发异常的上一位置中堆栈跟踪的末尾 --- 在 System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task) 在 System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task) 在 System.Runtime.CompilerServices.TaskAwaiter.ValidateEnd(Task task) 在 Microsoft.Web.WebView2.Wpf.WebView2.<>c__DisplayClass32_0.<g__Init|0>d.MoveNext() --- 引发异常的上一位置中堆栈跟踪的末尾 --- 在 System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task) 在 System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task) 在 System.Runtime.CompilerServices.TaskAwaiter.GetResult() 在 IOTContainer.View.EdgeWindow.d__2.MoveNext()

this is part of my codes:

  private async void Window_Loaded(object sender, RoutedEventArgs e)
  {
    if (webView.CoreWebView2 == null)
    {
        await webView.EnsureCoreWebView2Async();
    }
    webView.CoreWebView2.Settings.AreDefaultContextMenusEnabled = false;
    webView.CoreWebView2.Settings.IsZoomControlEnabled = false;
    webView.CoreWebView2.Settings.IsPinchZoomEnabled = false;
    webView.CoreWebView2.Settings.IsGeneralAutofillEnabled = false;
    webView.CoreWebView2.Settings.IsPasswordAutosaveEnabled = false;

    webView.CoreWebView2.SetVirtualHostNameToFolderMapping("navigation", Path.Combine(AppDomain.CurrentDomain.BaseDirectory, "www"), CoreWebView2HostResourceAccessKind.Allow);
    webView.CoreWebView2.Navigate("http://navigation/index.html");
  }
 private async void Window_Closed(object sender, EventArgs e)
    {
        if (null != webView && null != webView.CoreWebView2)
        {
            webView.CoreWebView2.Stop();
            await webView.CoreWebView2.Profile.ClearBrowsingDataAsync();
            //webView.Dispose();
        }
    }